How A Shoe Sole Is Made
We take for granted the rubber on the bottom of our shoes — the material that grips and keeps us steady in tennis shoes, running shoes, casual shoes and even dress shoes. But how did the rubber sole of a shoe come to be so commonplace? And how do modern manufacturers mass produce the millions of rubber soles that need to be churned out each year in order to keep the world’s feet secure and comfortable?
The shoe manufacturing process goes back to 1844, when Charles Goodyear made a breakthrough after years of experimentation. He used a process he called “vulcanization” to heat natural rubber in order to mix it with sulfur — a concoction that helped create the type of rubber used in shoe soles today.
We still use the same vulcanization method to create rubber for shoe sole material. Goodyear’s combination of curing, mixing and heating leads to the rugged shoe soles we know today.
The Process of Shoe Manufacturing
We are a chemical specialty company that focuses on the mold release for polyurethane integral skin molding for shoe soles. We’re a small but important part of the process that helps shoes reach their completion and find their way onto your feet. The process includes:
- Rubber Outsole Pressing: The shoe molds are used to create two parts — the insole and outsole. First, the outsole is prepped with color for a logo as well as a background color. The middle plate is closed with the colors added, and then raw rubber is placed into the mold, where it will soon flow in to form the outsole. Close the full mold and heat for a short time to create the outsole. Once out of the oven, the excess rubber is cut away to leave a perfectly formed outsole.
- Rubber Insole Pressing: Instead of adding a logo and background color, the insole requires a heel color. Add raw rubber that will form the forefront and place the mold back into the heat to form the insole.
- Fusing: Now it’s time to fuse the insole and outsole to form a finish rubber sole product. Once fused, simply cut away the excess rubber, and enjoy the beautiful (and comfortable) rubber sole that’s made not so differently than how Charles Goodyear made his rubber more than 150 years ago.
This process can vary depending on the type of sole you’re creating and the type of shoe you’re creating it for. But the basic elements of the process are the same, and you can find this basic process in place at factories around the world. The rubber mixing and pressing operations are messy, with lots of moving parts and lots of excess, which is why the process is so often outsourced. But because these factories specialize in creating rubber soles, they can do high-volume work and crank out an unbelievable number of soles each day — efficiently and accurately.
Custom Mold Release Solutions
At W.N. Shaw, we specialize in polyurethane, rubber and composite molding, which includes release agents for both single- and dual-density unit soles. Since 1985, we’ve been serving manufacturers with custom model release agents, adding value through our cost-effective solutions and advanced technologies.
We can create custom mold release solutions for manufacturers operating in a range of industries, shoe production and beyond. We can also adapt as new technologies and innovations become available. We share your urgency in creating the most effective, most affordable processes possible.
We have hands-on experience gained on our own shop floor, where these custom release agents are tested and formulated. As we perfect these release agents, we make them available to manufacturers in the USA and Canada, and we make them available through distributors in Mexico, China, Japan, Asia, South American and Europe. Our global reach gives us real-time experience and knowledge into what’s working and what’s not, as well as the agents, products and capabilities that manufacturers most value.
We are proud to carry on the tradition of high-quality shoe sole production, honoring the legacy of Charles Goodyear. As a part of the shoe sole production process, we place an emphasis on attention to detail and delivering results that reflect the utmost in care. If you need custom mold release agents for the production of shoe soles, turn to W.N. Shaw — the company that offers the experience, knowledge and resources to get the job done.